Process for the manufacture of slidable rubber



Sept. 29, 1942. w. DEISSNER PROCESS FOR THE MANUFACTURE OF SLIDABLE] RUBBER Filed April 11, 1939 Patented Sept. 29,

raociiss roa run murderous or SLIDABLE amen Wilhelm Deissner, Berlin-Hehterfelde. Germany;

, vested in the Allen Property Application April 11, 1939, Serial No. 201.351

. In Germany February 5, 1938 1 Claim.

This invention relates'to a process for the manufacture of a slidable antifrictional technical rubber for use, for example, for window guides, pneumatic mail containers and so forth. Ac-

cording to the inventionthe outer surface of the rubber which is. mixed with fibres is removed.

Preferably a soft rubber which contains more than-25% of fibresisused.

According to a further feature of the invention, the fibres may be substantially at right angles to the surface of the rubber which is made slidable, that is to say mayextend from the surface like the bristles of a brush. This result can be obtained in accordance also with the invention, for example, by cutting a rolled or extracted rubber sheet mixed with fibres into narrow strips corresponding to the thickness of the rubber desired and joining the individual strips together. in such a manner that the cut surfaces together form the new outer surface and thereafter vulcanising the strips; together. After the vulcanising, the continuous rubber layer which is formed is removed, whereupon the fibres lie substantially at right angles to the outer sur- 25 then vulcanized.

faces of the sheet formed and stand out like the bristles of a brush.

The invention accordingly also consists in a slidableantifrictional technical rubber composed of vulcanised soft rubber mixed with fibres the outer skin of which is removed.

The invention resides also in a slidable rubber, the essential feature of which is that it is provided with fibres extending approximately at right angles, like the bristles of a brush, to the slidable surface.

Finally, the inventionconsists -also in a soft rubber mixed with fibres which is composed of individual strips which correspond to the thickness of the desired product and are so assembled that the cut surfaces formed on making the strips lie on the outside of the finished product.

By means of the invention there is obtained a rubber which can be used for all purposes for which a rubber .which is slidable or has an agree- -ab1e grip or feel is required. The invention is therefore not limited in any way to the uses previously mentioned. In addition to its slidability the rubber also has a warm, agreeable velvet-like feel which is also of importance,,when the rubber is to be used for making, for example, rubber toys, rubber clothing, rubber shoes and rubber belts and the like.

When the rubber is formed from strips the rubber becomes elastic again, so that after the process of the present invention has been car- 15 invention is used for other purposes.

ried out an elastic, fibre-containing. slidable rubher is obtained.

The rubber filled with fibres of which the outer skin is removed presents a material which slides well, even if the fibres run more or less paral- By placing the fibres in such a manner that they he more or less at lel,to the outer surface.

right angles to the outersurface there is produced a rubber material which has a velvet-like p arance and feel.

Whenusing the material of the invention for a window guide, it need not be provided with a separate textilecovering of plush, felt or the like.

The same holds good when the rubber of the A particularly important purpose is for the sliding rings of pneumatic mail containers.

20 A method for producing a slidable rubber article according to my invention is as follows:

Soft rubber is in a well known manner mixed with fibres of cotton or the like, then brought in sheet form of say 3 or 4 mm. thicknes and face is produced on the sheet which consists of more or less pure rubber. This outer surface is then removed by grinding disks or grinding rolls on those points which are to be made slidable.

By the-grinding the fibres .come to and project from the outer surface of the article and make it slidable.

According to a preferred method the said vulcanined sheet preferably after removing the outer layer of pure rubber is cut into small strips of equal breadth of say 3 to 4 mm. These strips are associated was to form with their cut surfaces new surfaces of a sheet the thickness of which corresponds to the breadth of the cut 40 strips. These strips are vulcanized together whereby the outer surfaces of the new sheet are again covered with a layer of pure rubber. When this layer is also removed by grind-ingor the like the fibres lie square to the outer surface of the article and project from the surface in a brushlike manner giving the article a smooth slidable character. The fact that the fibres project from the ground surfacesis due to the fact that the grinding disks do not affect the fibres in the 60 same degree as the rubber and-take away more:

from the rubber than from the fibres.

Some embodiments of-the invention a'r'e dis closed in the, attached drawing in which Fig. 1 is a plan view of a rubber plate accordin: to the invention; 4

for which --the rubber of the present invention can be used.

while vulcanizing an outer sur- Fig. 2 is a section along line 2-2- of Fig.- 1, Fig. 3 is a perspective view of a plate made 01 rubber which is mixed with fibres and in which the dotted lines indicate cutting planes,

Fig. 4 is a perspective view of a plate composed of strips cut out according to Fig. 3,

Fig. 5 is a perspective view 01' the same plate as shown in Fig. 4 after the strips being vulcanized together and after a further treatment of the plate.

The diil'erent figures are not supposed to be on natural size and they are not drawn to the same scale.

In Figs. 1 and 2 the vulcanized rubber plate which is mixed with fibres is designated as a whole by the letter a. The upper rubber skin d is shown to have been removed in the region b by grinding or the like, so that fibres 0 project irregularly beyond the outer surface of the plate. After the removal of the rubber skin at from the entire plate, the plate has been found to possess a great slidability with respect to adjacent bodies which may rest against it.

3 shows a plate made of rubber and fibres which is out along the dotted lines into strips ,f| to j-9. These strips are then placed on edge and put together in position as shown in Fig. 4. Hereupon the strips j-i to f-! are vulcanized together. in their new relative position. During this vulcanizing procedure a'thin rubber skin is again formed on the outer surface of the plate. After grinding oil or removing otherwise this rubber skin, the fibres project outwardly beyond the surface 01' the main body of the plate, more or less in a direction vertical to such surface and parallel to each other asitisindicated atoinFig.5.

I claim: 1

In a method for producing an antifrictional technical article made of vulcanized soft rubber which is mixed with fibres. producing of a sheet of rubber mixed with fibres, cutting the sheet into strips, associating these strips so as to form with their cut-surfaces new surfaces of a sheet the thickness of which corresponds to the breadth of the cut strips, vulcanizing together these strips and removing the layer of rubber originated by said vulcanizing' on those parts oi. the strips which are intended to be slidable.

WILHEIM DEISSNER. 

